... to set/check the max 'no-load' RPM?

I'd like to go through and make sure the governing settings are right on my engine, but the idea of dropping it into neutral and burying the pedal just doesn't make me feel good. The manual is full of cautions not to let the engine hit 5000rpm for more than an instant lest bad things happen. How much of a risk is it to bring my little 220D up to 5000rpm?

Today I did check the maximum full load RPM, and she topped out at 4000rpm on level ground, so I know that I need to make some adjustments to the governor since I should have another 350rpm before it stops.
I do not plan to use the redline often (or ever) but it seems that if the governing RPM is too low, then I either need to have the IP set to inject more fuel, or loosen the full load screw to let the TB open a bit further, either of which would seem to affect power throughout the entire RPM scale.
The problem is that I do not know which adjustment is the proper one to get the engine back to proper MB specs without checking the no load max RPM...